Method for producing (hydroxymethyl)polysiloxanes

ABSTRACT

A method for producing (hydroxymethyl)polysiloxanes of the general formula I
 
(SiO 4/2 ) k (R 1 SiO 3/2 ) m (R 1   2 SiO 2/2 ) p (R 1   3 SiO 1/2 ) q [O 1/2 —(SiR 2   2 —X—Y—) a SiR 2   2 —CH 2 —OH] s [O 1/2 H] t   formula I,
 
includes reacting silanol-containing organosiloxanes of the general formula II
 
(SiO 4/2 ) k (R 1 SiO 3/2 ) m (R 1   2 SiO 2/2 ) p (R 1   3 SiO 1/2 ) q [O 1/2 H] r   formula II
 
with cyclic or acyclic compounds that include at least one unit of the general formula III
 
Z—[O—CH 2 —SiR 2   2 ] n —Y  formula III

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the national phase filing of international patentapplication No. PCT/EP2010/065451, filed 14 Oct. 2010, and claimspriority of German patent application number 10 2009 046 254.6, filed 30Oct. 2009, the entireties of which applications are incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention relates to a method for producing(hydroxymethyl)polysiloxanes and (hydroxymethyl)-polysiloxane resins.

BACKGROUND OF THE INVENTION

(Hydroxyalkyl)polysiloxanes and (hydroxyalkyl)-polysiloxane resinsincorporate as structural element units of the formulasiloxane-(SiR^(i) ₂)—R^(ii)—OH,where R^(i) is alkyl or aryl, generally methyl, and R^(ii) is ahydrocarbon moiety which may contain or be substituted with heteroatomsand which is attached to the silicon atom in the (SiR^(i) ₂) group via acarbon atom. The presence of R^(ii) between the silicon atom and thedepicted OH group has the effect that the bond attaching the OH group tothe siloxane scaffold is hydrolysis stable. When the OH group is reactedwith other compounds, the bond attaching the resulting products to thesiloxane scaffold will likewise be hydrolysis stable.

The R^(ii) group is in effect a structure-conferring factor whichco-determines not only the properties of the (hydroxyalkyl)polysiloxane,or respectively (hydroxyalkyl)polysiloxane resin, but also theproperties of descendant products obtainable using the(hydroxyalkyl)polysiloxane or respectively the(hydroxyalkyl)polysiloxane resin. It is especially the mobility ofR^(ii) as well as the organic character of R^(ii) which influences theseproperties. When, for example, the mobility of R^(ii) and/or the organiccharacter of a (hydroxyalkyl)polysiloxane or respectively of a(hydroxyalkyl)polysiloxane resin or descendant products thereof are tobe kept to a minimum, very small R^(ii) moieties are ideal, and thechoice of R^(ii) as CH₂ is especially advantageous. A further advantageof this choice for R^(ii) is that small structural units mean lowerreaction volumes for the same amount of substance of R^(ii)-attached OHgroups and hence enhanced space-time yields both in the production of(hydroxyalkyl)polysiloxanes or respectively of(hydroxyalkyl)polysiloxane resins and in the production of descendantproducts thereof.

(Hydroxyalkyl)polysiloxanes and (hydroxyalkyl)-polysiloxane resins whereR^(ii) is CH₂ are hereinafter referred to as(hydroxymethyl)polysiloxanes and (hydroxymethyl)polysiloxane resins,respectively.

Methods for producing (hydroxyalkyl)polysiloxanes and(hydroxyalkyl)polysiloxane resins are described in the literature.

The references EP 629 648, EP 768 347, DE 101 09 842, DE 10 2004 029 259and DE 10 2005 045 334 describe methods whereinpolysiloxanes/polysiloxane resins or fillers that bear Si—OH groups arereacted with cyclic or linear compounds of the structure *[SiR^(i)₂—R^(ii)—O—]_(φ)*=end groups or ring closure; φ≧1). None of thesereferences describes a method wherein R^(ii) is CH₂.

Methods for producing (hydroxymethyl)polysiloxanes and(hydroxymethyl)polysiloxane resins (R^(ii) is CH₂) are likewisedescribed in the literature.

The references DE 1 213 406, DE 1 236 505, DE 1 251 320, DE 879 839 andDE 1 233 395 describe the production of (hydroxymethyl)polysiloxanes andof (hydroxymethyl)polysiloxane resins by reaction of(halomethyl)polysiloxanes and of (halomethyl)polysiloxane resins,respectively, with metal hydroxides (DE 1 213 406) or with (i) metalcarboxylates and (ii) transesterification of the resultant(acyloxymethyl)polysiloxanes and (acyloxymethyl)polysiloxane resins withalcohols (DE 879 839; cf. production of (acyloxymethyl)-polysiloxanesand of (acyloxymethyl)polysiloxane resins by reaction of(halomethyl)polysiloxanes and of (halomethyl)polysiloxane resins,respectively, with ammonium carboxylates: DE 1 199 772, U.S. Pat. No.2,833,802). However, the siloxane scaffold will generally undergorearrangements under the conditions described.

DE 1 236 505 and DE 1 251 320 describe the production of(hydroxymethyl)polysiloxanes and of (hydroxymethyl)-polysiloxane resinsrespectively by transesterification of (acyloxymethyl)polysiloxanes andof (acyloxymethyl)-polysiloxane resins respectively with alcohols undercatalysis by arylsulfonic acids. DE 1 236 505 describes inter alia amethod wherein linear poly(dimethylsiloxane) (α,ω-OH-terminated) isreacted with an (acyloxymethyl)dimethylethoxysilane, and theSi-(acyloxymethyl) groups are transesterified with methanol toSi-(hydroxymethyl) groups (Si—CH₂—OH) (reaction “f)” in DE 1 236 505).However, drastic conditions (toluenesulfonic acid and heating) have tobe used to transesterify the Si-(acyloxymethyl) groups. Yet under suchconditions the siloxane scaffold will generally become rearranged.

DE 1 233 395 describes the production of (hydroxymethyl)polysiloxanesand of (hydroxymethyl)-polysiloxane resins by reaction of(acyloxymethyl)polysiloxanes and of (acyloxymethyl)-polysiloxane resinsrespectively with alkali metal boronates and hydrolysis of the resultantprimary product. However, alkali metal boronates are costly reagents andmoreover can attack and change the siloxane scaffold.

DE 1 227 456, DE 879 839 and SU 1 512 982 describe the production of(hydroxymethyl)polysiloxanes and of (hydroxymethyl)polysiloxane resinsby equilibration of, for example,1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane with cyclic oracyclic organopolysiloxanes. However, for such an equilibration reactionto take place it is necessary for the siloxane formation of the1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane to cleave. Yet theconditions under which this disiloxane bond is cleaved also causesiloxane bonds to rearrange/cleave in the organopolysiloxane which is tobe converted.

What is common to the methods described for producing(hydroxymethyl)polysiloxanes and (hydroxymethyl)-polysiloxane resins isthat the reaction conditions tend to cause rearrangements of thesiloxane scaffold, and so the methods do not lead to defined products.Furthermore, the resulting ≡SiCH₂OH groups are frequently not releasedquantitatively from the corresponding precursor compounds (e.g.,≡SiCH₂—Oacyl or ≡SiCH₂-halogen), and/or the resulting ≡SiCH₂OH groupsreact further under the reaction conditions (e.g., with HCl to form≡SiCH₂Cl groups, with sulfuric acid to form ≡SiCH₂OCH₂Si≡ groups or withhydroxides to cleave the Si—C bond in SiCH₂OH groups to Si—OH groups),and so the product does not have the theoretically expectednumber/concentration of ≡SiCH₂OH groups. Furthermore, reagent residuesand/or catalyst residues in the product frequently lead torearrangement, cleavage, condensation or equilibration of the siloxanescaffold, and so the product properties of (hydroxymethyl)polysiloxanesand of (hydroxymethyl)polysiloxane resins produced by literature methodsfrequently change during storage. All these inventions hinder or preventthe further conversion of the (hydroxymethyl)polysiloxanes or(hydroxymethyl)polysiloxane resins obtained in the prior art intodefined descendant products, it holds particularly for descendantreactions at the SiCH₂OH group.

SUMMARY OF THE INVENTION

The problem addressed by the invention is therefore that of improvingthe prior art, providing a method for producing(hydroxymethyl)polysiloxanes and (hydroxymethyl)polysiloxane resinswhich leads to defined products, preferably in high purity andpreferably with high product stability.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a method for producing(hydroxymethyl)polysiloxanes and (hydroxymethyl)-polysiloxane resins ofthe general formula I(SiO_(4/2))_(k)(R¹SiO_(3/2))_(m)(R¹ ₂SiO_(2/2))_(p)(R¹₃SiO_(1/2))_(q)[O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR²₂—CH₂—OH]_(s)[O_(1/2)H]_(t)  formula I,which comprises reacting silanol-containingorganosiloxanes/organosiloxane resins of the general formula II(SiO_(4/2))_(k)(R¹SiO_(3/2))_(m)(R¹ ₂SiO_(2/2))_(p)(R¹₃SiO_(1/2))_(q)[O_(1/2)H]_(r)  formula IIwith cyclic or acyclic compounds which include at least one unit of thegeneral formula IIIZ—[O—CH₂—SiR² ₂]_(n)—Y  formula IIIwhere

-   -   R¹ denotes a hydrogen atom or a cyclic or acyclic, linear or        branched, aromatic or aliphatic or olefinic, saturated or        unsaturated C₁-C₂₀ hydrocarbon, C₁-C₂₀ hydrocarbonoxy or C₄-C₄₀        polyether moiety optionally substituted with Q¹ and optionally        interrupted by one or more heteroatom-containing groups Q²,    -   R² denotes a cyclic or acyclic, linear or branched aromatic or        aliphatic or olefinic, saturated or unsaturated C₁-C₂₀        hydrocarbon, C₁-C₂₀ hydrocarbonoxy, C₄-C₄₀ polyether or Si₁—Si₂₀        siloxanyl moiety optionally substituted with Q¹, optionally        interrupted by one or more heteroatom-containing groups Q² or        containing one or more heteroatom-containing groups Q²,    -   Q¹ denotes a heteroatom-containing monovalent moiety,    -   Q² denotes a heteroatom-containing divalent moiety or a        heteroatom-containing trivalent moiety,    -   Z represents hydrogen, a group X—SiR² ₂—, or combines with Y to        represent a bonding electron pair,    -   X represents a group R², a siloxane group or a bonding electron        pair to Y or may be bonded to Y or X combines with Y to denote        an oxygen atom or denotes an oxygen atom attached to Y,    -   Y may assume meanings selected from the meanings of R² or Q¹ or        Q² or represents a siloxane moiety or a hydrolysable group        inclusive hydroxyl or combines with Z to represent a bonding        electron pair and may be attached to Z via X and may be        interrupted by one or more optionally substituted siloxane        groups or combines with X to denote an oxygen atom,    -   with the proviso that Y in the case of n=1 denotes a        hydrolysable group or a siloxane moiety which contains at least        one hydrolysable group or combines with X to denote an oxygen        atom or is attached to X or combines with Z to represent a bond,    -   s assumes values of at least 1,    -   r assumes values of at least 1,    -   n assumes values of at least 1,    -   t assumes values of at least 0,    -   n assumes values of at least 1,    -   the sum s+t assumes the value of r,    -   k, m, p, q denote values not less than zero, with the proviso        that the sum k+m+p+q denotes a sum of at least 2,    -   a assumes the value 0 or 1.

The definitions whereby two groups, for example X, Y and/or Z, combinein the abovementioned possible combinations to form a bond or an oxygenatom can be elucidated using the example of compounds 1 and 2:

In compound 1 all R² moieties are methyl, n is 2 and Y combines with Zto represent a bonding electron pair. In compound 2, R² is methyl, n is1, Z represents an X—SiR² ₂— group (again with R² being methyl) and Xcombines with Y to denote an oxygen atom.

Compounds that include at least one unit of the general formula III arehereinbelow called “compounds of formula III” for simplicity.

The compounds of formula II and of formula III or mixtures containingthese compounds may be prepared, mixed and added to each or one anotherin any order, optionally even repeatedly, optionally even alternatingly,in the method of the present invention. The method of the presentinvention utilizes at least one compound of formula II and at least onecompound of formula III; it is also possible to use two, three, four,five, six or more compounds of formula II or of formula III,simultaneously or in succession, optionally even repeatedly, optionallyeven alternatingly. The method of the present invention produces atleast one (hydroxymethyl)polysiloxane/(hydroxymethyl)polysiloxane resinof formula I; it is also possible for two, three, four, five, six ormore compounds of formula I to be produced side by side. The compoundswhich are used of formula III can be free of solvolysates or for exampleinclude their solvolysates, for example with alcohols, water orsilanols.

When compounds containing units of the general formula III are used forfunctionalizing Si—OH groups in organosiloxanes/organosiloxane resins ofthe general formula II, these react surprisingly easily and specificallywith good yields with silanol groups to form carbinols.

When compounds containing units of the general formula III are used forfunctionalizing Si—OH groups in organosiloxanes/organosiloxane resins ofthe general formula II, the CH₂OH groups in the (hydroxymethyl)siloxaneunits produced by the method of the present invention are generated bySi—O bond cleavage and O protonation of a grouping of the structureSi(R² ₂)CH₂O—Si, or the CH₂OH groups are already present as such when Zin formula III is chosen to be hydrogen.

This distinguishes the method of the present invention from the priorart methods for producing (hydroxymethyl)polysiloxanes and(hydroxymethyl)poly-siloxane resins. The prior art methods for producing(hydroxymethyl)polysiloxanes or (hydroxymethyl)poly-siloxane resinsutilize or produce precursor siloxanes which bear a grouping of thestructure siloxane-CH₂-A. The group A therein constitutes an acyloxyradical or a halogen atom and is converted into OH groups under harshconditions, for example with alkali metal hydroxides (A=halogen) or withalcohols by acid catalysis or with boron hydrides (A=acyloxy). The harshreaction conditions frequently lead to rearrangements of the siloxanescaffold or to unintended descendant reactions at the producedhydroxymethyl groups such as, for example, cleavage of Si—C bonds.Furthermore, siloxanes comprising a siloxane-CH₂-A (A=halogen oracyloxy) grouping are not standard products, but have to be specificallyproduced as a precursor. In contradistinction thereto, the method of thepresent invention provides for surprisingly easy conversion of SiOHgroups into (hydroxymethyl)siloxane units, so that for example the SiOHgroups to be functionalized which are to be converted into(hydroxymethyl)siloxane units are themselves sufficiently reactive toeffect the generation of CH₂OH groups as described, although promotersor catalysts may optionally be used. Moreover, the organopolysiloxanesor organopolysiloxane resins of formula II used in the method of thepresent invention are standard products in the silicone industry andaccordingly do not have to be specially produced as a precursor for thesynthesis of (hydroxymethyl)polysiloxanes or(hydroxymethyl)poly-siloxane resins.

R¹ and R² are preferably of 1 to 12 carbon atoms, especially 1 to 6carbon atoms, preferably at just carbon atoms and hydrogen atoms, or onealkoxy oxygen atom and otherwise just carbon atoms and hydrogen atoms.

Preferably R¹ and R² are straight-chain or branched or cyclic C₁-C₆hydrocarbon moieties. Methyl, ethyl, phenyl, allyl and vinyl arepreferred for R¹ and methyl is particularly preferred. Methyl, ethyl,phenyl, allyl, vinyl, methoxy and ethoxy are preferred for R² andmethyl, ethyl, phenyl, allyl and vinyl are particularly preferred,especially methyl.

Preference is given to producing compounds of the general formula Iwhere R¹ and R² are each methyl.

Q¹ is preferably a fluorine, chlorine, bromine, iodine, cyanato,isocyanato, cyano, nitro, nitrato, nitrito, silyl, silylalkyl,silylaryl, siloxy, siloxaneoxy, siloxyalkyl, siloxaneoxyalkyl,siloxyaryl, siloxaneoxyaryl, hydroxyl, alkoxy, aryloxy, acyloxy,S-sulfonato, O-sulfonato, sulfato, S-sulfinato, O-sulfinato, amino,alkylamino, arylamino, dialkylamino, diarylamino, arylalkylamino,acylamino, imido, sulfonamido, imino, mercapto, alkylthio or arylthiosubstituent, O-alkyl-N-carbamato, O-aryl-N-carbamato,N-alkyl-O-carbamato, N-aryl-O-carbamato, optionally alkyl- oraryl-substituted P-phosphonato, optionally alkyl- or aryl-substitutedO-phosphonato, optionally alkyl- or aryl-substituted P-phosphinato,optionally alkyl- or aryl-substituted O-phosphinato, optionally alkyl-or aryl-substituted phosphino, hydroxycarbonyl, alkoxycarbonyl,aryloxycarbonyl, cyclic or acyclic carbonate, alkylcarbonato orarylcarbonato substituent, more preferably a fluorine, chlorine,bromine, iodine, cyanato, isocyanato, cyano, silyl, silylalkyl,silylaryl, siloxy, siloxaneoxy, siloxyalkyl, siloxaneoxyalkyl,siloxyaryl, siloxaneoxyaryl, hydroxyl, alkoxy, aryloxy, acyloxy,S-sulfonato, sulfato, amino, alkylamino, arylamino, dialkylamino,diarylamino, arylalkylamino, acylamino, imido, sulfonamido, imino,mercapto, alkylthio or arylthio substituent, O-alkyl-N-carbamato,O-aryl-N-carbamato, N-alkyl-O-carbamato, N-aryl-O-carbamato, optionallyalkyl- or aryl-substituted P-phosphonato, optionally alkyl- oraryl-substituted O-phosphonato, optionally alkyl- or aryl-substituted P—optionally alkyl- or aryl-substituted phosphino, hydroxycarbonyl,alkoxycarbonyl, or aryloxycarbonyl substituent.

Q² is preferably a heteroatom-containing divalent radical, for example—O—, —S—, —N(R⁴)—, —C(O)—, epoxy, —C(O)—O—, —O—C(O)—O—, —O—C(O)—N(R⁴)—,—N(R⁴)—C(O)—O—, —S(O)—, —S(O)₂—, —S(O)—O—, —S(O)₂—O—, —O—S(O)₂—O—,—C(O)—N(R⁴)—, —S(O)₂—N(R⁴)—, —S(O)₂—N[C(O)R⁶]—, —O—S(O)₂—N(R⁴)—,—N(R⁴)—S(O)₂—O—, —P(O)(OR⁵)—O—, —O—P(O)(OR⁵)—, —O—P(O)(OR⁵)—O—,—P(O)(OR⁵)—N(R⁴)—, —N(R⁴)—P(O)(OR⁵)—, —O—P(O)(OR⁵)—N(R⁴)—,—N(R⁴)—P(O)(OR⁵)—O—, —N[C(O)R⁶]—, —N═C(R⁶)—O—, —C(R⁶)═N—O—,—C(O)—N[C(O)R⁶]—, —N[S(O)₂R⁷]—, —C(O)—N[S(O)₂R⁷]—, —N[P(O)R⁸ ₂]—, —Si(R²₂)—, —[Si(R² ₂)O]_(o)—, —[OSi(R² ₂)]_(o)—, —[OSi(R² ₂)]_(o)O—, morepreferably —O—, —S—, —N(R⁴)—, —C(O)—, epoxy, —C(O)—O—, —O—C(O)—N(R⁴)—,—N(R⁴)—C(O)—O—, —S(O)—, S(O)₂—, S(O)₂—, S(O)₂—O—, —O—S(O)₂—O—,—C(O)—N(R⁴)—, —S(O)₂—N(R⁴)—S(O)₂—N[C(O)R⁶]—, —O—S(O)₂—N(R⁴)—,—N(R⁴)—S(O)₂—O—, —P(O)(OR⁵)—O—, —O—P(O)(OR⁵)—, —O—P(O)(OR⁵)—O—,—N[C(O)R⁶]—, —N═C(R⁶)—O—, —C(R⁶)═N—O—, —C(O)—N[C(O)R⁶]—, —N[S(O)₂R⁷]—,—C(O)—N[S(O)₂R⁷]—, —N[P(O)R⁶ ₂]—, —Si(R² ₂)—, —[Si(R² ₂)—O]_(o)—,—[OSi(R² ₂)]_(o)—, —[OSi(R² ₂)]_(o)O—, where R⁴, R⁵ and R⁶ representhydrogen or optionally substituted C₁-C₂₀-alkyl or C₆-C₂₀-aryl moieties,R⁷ represents an optionally substituted C₁-C₂₀-alkyl or C₆-C₂₀-arylmoiety, R⁸ represents an optionally substituted C₁-C₂₀-alkyl,C₆-C₂₀-aryl, C₁-C₂₀-alkoxy or C₆-C₂₀-aryloxy moiety and o represents anumber from 1 to 100, preferably 1 to 10, or a heteroatom-containingtrivalent radical, for example —N═ or —P═.

The hydroxyl-functional organosiloxane of the general formula II may befor example linear, cyclic or branched.

The sum of k, m, p, q, s and t is preferably a number from 3 to 10 000,more preferably 4 to 1000 and even more preferably 5 to 200. The sum ofk, m, p, q and r is preferably a number from 3 to 10 000, morepreferably 4 to 1000 and even more preferably 5 to 200. The sum of k, m,p and q is preferably a number from 2 to 10 000, more preferably 3 to1000 and even more preferably 4 to 200. The recited sums relate to theaverage chain lengths (number average) of the respective siloxanes. Itis preferable for the groups [O_(1/2)H] or the groups [O_(1/2)—(SiR²₂—X—Y—)_(a)SiR² ₂—CH₂—OH] to be attached to (R¹ ₂SiO_(2/2)) groups.

k is preferably a number from 0 to 50, more preferably 0 to 5, even morepreferably 0 to 1, especially 0.

m is preferably a number from 0 to 100, more preferably 0 to 10, evenmore preferably 0 to 1, especially 0.

p is preferably a number from 0 to 10 000, more preferably 1 to 1000,even more preferably 2 to 200.

q is preferably a number from 0 to 100, more preferably 0 to 10, evenmore preferably 0 to 1, especially 0.

s is preferably a number from 1 to 100, more preferably 1 to 10, evenmore preferably 1 to 2, especially 2.

r is preferably a number from 1 to 100, more preferably 1 to 10, evenmore preferably 1 to 2, especially 2.

t is preferably a number from 0 to 99, more preferably 0 to 9, even morepreferably 0 to 1, especially 0.

The variable a in formula I preferably assumes the value 0. It ispreferable for the groups [O_(1/2)H] to be attached to (R¹ ₂SiO_(2/2))groups. It is preferable for the groups [O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR²₂—CH₂—OH] to be attached to (R¹ ₂SiO_(2/2)) groups.

The variable n in formula III preferably assumes values not less than 2,more preferably values from 2 to 100 and even more preferably from 2 to20. The variable n may assume for example the values 1, 2, 3, 4, 5 or6-20 or greater.

Y in formula III preferably combines with Z to denote a bond or Zdenotes an X—SiR² ₂— group, where X combines with Z to denote an oxygenatom or a siloxane group bonded to Z; it is more preferable for Y tobind with Z to denote a bond. The latter particularly preferable caseresults in cyclic compounds of formula III which consist exclusively of[O—CH₂—SiR² ₂]_(n) units.

A preferred variant of an organosiloxane of the general formula II is alinear silicone polymer where k and m are equal to 0, p is not less than1, q is 0 or 1 and r is 1 or 2 subject to the condition that r+q is 2,while it is more preferable for q to be 0, p to be not less than 2 and rto be 2. Preferably p here is in the range from 3 to 10 000, morepreferably in the range from 4 to 1000 and even more preferably in therange from 5 to 200. The recited p values relate to the average chainlengths (number average) of the siloxanes. Preferably r is s. Thepreferred organosiloxanes of the general formula II may form either amonomodal distribution or a bimodal distribution or a multimodaldistribution, while at the same time they may be in a narrow or verybroad molar mass distribution.

A further preferred variant of a branched organosiloxane used of thegeneral formula II is an organosilicone resin. This resin may consist ofmultiple units, as shown by the general formula II, in which case themole percentages of the units present are indicated by the indices k, m,p, q, r, s and t. Preference is given to a value of 0.1 to 20 mol % ofunits r, based on the sum total of k, m, p, q and r. At the same time,however, k+m has to be >0. In the production of the organosiloxane resinof the general formula I, s has to be >0 and s+t has to be equal to r.

Preference is given to producing resins wherein 5 mol %<k+m<90 mol %,based on the sum total of k, m, p, q, s and t and t is preferably 0. Ina particularly preferred case, R¹ and R² are each methyl.

The units (SiO_(4/2)), (R¹SiO_(3/2)), (R¹ ₂SiO_(2/2)), in formula I andrespectively the units (SiO_(4/2)), (R¹SiO_(3/2)), (R¹ ₂SiO_(2/2)) informula II can also for example appear with multiple repetition, forexample as blocks or as individual or as alternating units.

The units (R¹ ₃SiO_(1/2)), [O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR² ₂—CH₂—OH],[O_(1/2)H] in formula I and respectively the units (R¹ ₃SiO_(1/2)),[O_(1/2)H] in formula II may appear for example at multiple points ofthe polymer backbone, for example in an ordered distribution or in arandom distribution.

In a preferred method for producing(hydroxymethyl)-polysiloxanes/(hydroxymethyl)polysiloxane resins, thesilanol-containing organosiloxanes/organosiloxane resins used of formulaII are compounds conforming to the following formula IIa:H[OSiR¹¹ ₂]_(α)OH  formula IIa,where α denotes whole-numbered values of 2 to 20 000 and R¹¹ denotesmethyl, ethyl, vinyl, allyl or phenyl.

α is preferably from 3 to 10 000, more preferably 4 to 1000 and evenmore preferably 5 to 200.

The values recited for a relate to the average chain lengths (numberaverage) of the siloxanes.

R¹¹ is preferably methyl, ethyl, vinyl or phenyl, more preferably methylor vinyl and even more preferably methyl.

Formula IIa emerges from formula II when, in formula II, the R¹¹moieties assume the meaning R¹¹ and k, m and q all assume the value 0, rassumes the value 2 and p assumes the value α, while α can assume thevalues as defined above.

In a preferred method for producing(hydroxymethyl)-polysiloxanes/(hydroxymethyl)polysiloxane resins, theformula III compounds used are compounds conforming to the followingformula IIIa:Z—[O—CH₂—SiR¹² ₂]_(n)—Y  formula IIIa,where R¹² may assume the meanings methyl, ethyl, vinyl, allyl, phenyl,methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy,tert-butoxy, n-pentoxy, tert-pentoxy or n-hexoxy,

and n, Y and Z may assume the same meanings as defined above.

R¹² is preferably methyl, ethyl, vinyl, allyl, phenyl, methoxy orethoxy, more preferably methyl, ethyl, vinyl, allyl or phenyl and evenmore preferably methyl.

n, Y and Z in formula IIIa preferably, more preferably and even morepreferably assume the meanings defined above in relation to formula IIIas more preferable and even more preferably respectively.

Formula IIIa emerges from formula III when, in formula III, the R²moieties assume the meaning R¹², while n, Y and Z may assume the samevalues as defined above in relation to formula III.

In a preferred method for producing(hydroxymethyl)polysiloxanes/(hydroxymethyl)polysiloxane resins, theformula I product produced are the following compounds of formula Ia:HOCH₂SiR¹² ₂[OSiR¹¹ ₂]_(α)OSiR¹² ₂CH₂OH  formula Ia,where α denotes whole-numbered values of 2 to 20 000 and R¹¹ and R¹²have the above-defined meanings, by reacting compounds of formula IIawith compounds of formula IIIa. α therein is preferably from 3 to 10000, more preferably 4 to 1000 and even more preferably 5 to 200.

The values recited for α relate to the average chain lengths (numberaverage) of the siloxanes.

The amount of substance ratio of compounds of formula II which wereselected from the possibilities defined for formulae IIa to compounds offormula III which were selected from the possibilities defined forformulae IIIa is preferably chosen such that the amount of substanceratio of silanol groups in formula IIa to the amount of substance ratioof [OCH₂SiR¹² ₂] units in formula IIIa, based on the number of theiroccurrences n in formula IIIa, is preferably in the range from 0.8 to1.2, more preferably in the range from 0.9 to 1.1 and even morepreferably 1.0. “Based on the number of their occurrences n in formulaIIIa” here is to be understood as meaning that for example for n=2 the[OCH₂SiR¹² ₂]_(n) unit is reckoned as two [OCH₂SiR¹² ₂] units, forexample for n=3 as three [OCH₂SiR¹² ₂] units, and so forth.

It is preferable for the compounds used as including a unit of thegeneral formula III to be compounds of the following general formulaeIV-VIII:

where

-   -   R¹ in the formula VIII may assume the same meanings as defined        above and in formula VIII assumes preferably, more preferably or        even more preferably the meanings defined above as respectively        preferable, more preferable or even more preferable for R¹,    -   R² in the formulae IV-VIII may assume the same meanings as        defined above and in the formulae IV-VIII preferably, more        preferably or even more preferably assumes the meanings defined        above as respectively preferable, more preferable and even more        preferable for R², or where R² in preferred embodiments assumes        the meaning R¹², with the meanings, preferably the preferred and        particularly preferred meanings defined above for R¹²,    -   β, γ, δ, ε may assume the same meanings as n as defined above,        and preferably the same meanings 1-100, more preferably 1-30 and        even more preferably the meanings 1-10,    -   i may assume a whole-numbered value not less than 2 and        preferably assumes the meanings 2-100, preferably 2-30 and more        preferably the meanings 2-10,    -   j in formula V denotes a whole-numbered value not less than 0        and preferably assumes the values not less than 1, more        preferably values of 1-20 and even more preferably values of        1-10,    -   k, m, p and q and their above-defined sum in formula VIII may        assume the same values as defined above and preferably, more        preferably and even more preferably, respectively, assume the        same values as defined above as preferable, more preferable and        even more preferable, respectively, for respectively k, m, p and        q and for their sum,    -   u in formula VIII may assume a value not less than 1 and        preferably assumes the meanings 1-20, more preferably 1-10 and        even more preferably the values 1 or 2,    -   v in formula VIII may assume a value not less than 0 and        preferably assumes the meanings 0-20, more preferably 0-10 and        even more preferably the values 0, 1 or 2,    -   w in formula VIII may assume a value not less than 0 and        preferably assumes the values 0-20, more preferably 0-10 and        even more preferably the value 0,    -   Y¹ in formula VI represents a moiety R², a moiety —O—(SiR²        ₂—CH₂—O)_(b)Z¹, a hydrogen atom or a hydrolysable group,        preferably a hydroxyl group, a C₁-C₂₀ alkoxy group, a C₆-C₂₀        aryloxy group or a C₁-C₄₀ polyether group, especially a hydroxyl        group, a methoxy group or an ethoxy group,    -   with the proviso that Y¹ when δ in formula VI assumes the        meaning 1 represents a hydrolysable group inclusive alkoxy,        aryloxy, or hydroxyl, or a hydrogen atom, or represents a moiety        —O—(SiR² ₂—CH₂—O)_(b)H with b not less than 2,    -   b represents values not less than 1 and preferably represents        values not less than 2, more preferably 2-30 and even more        preferably 2-10,    -   Y² in formula VII represents a moiety R², a moiety —O—(SiR²        ₂—CH₂—O)_(c)Z², a hydrogen atom or a hydrolysable group        inclusive hydroxyl, preferably a hydroxyl group, a C₁-C₂₀ alkoxy        group, a C₆-C₂₀ aryloxy group or a C₁-C₄₀ polyether group,        especially a hydroxyl group, a methoxy group or an ethoxy group,    -   c represents values not less than 1 and preferably represents        values not less than 2, more preferably 2-30 and even more        preferably 2-10,    -   Z¹ represents a hydrogen atom, a silyl group attached via a        silicon atom or a siloxanyl group attached via a silicon atom        and preferably represents a hydrogen atom,    -   Z² represents a hydrogen atom, a silyl group attached via a        silicon atom, a siloxanyl group attached via a silicon atom,        or—when ε in formula VII assumes a value not less than 2 or Y²        is a hydrolysable group— represents an alkyl, aryl or acyl group        optionally substituted with Q¹ or interrupted by one or more        groups Q², and preferably represents a hydrogen atom,    -   Z³ represents a hydrogen atom, a silyl group attached via a        silicon atom, a siloxanyl group attached via a silicon atom,        or—when i in formula VIII assumes a value not less than        3—represents an alkyl, aryl or acyl group optionally substituted        with Q¹ or interrupted by one or more groups Q², and preferably        represents a hydrogen atom,    -   Z⁴ may assume the same meanings as Z¹,    -   a may assume the same meanings as defined above and preferably        assumes the value 0.

i may assume for example the values 2, 3, 4, 5, 6, 7, 8, 9, 10 orgreater.

j, v, w may assume for example the values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10 or greater.

β, γ, δ, ε, u may assume for example the values 1, 2, 3, 4, 5, 6, 7, 8,9, 10 or greater.

When Z⁴ assumes meanings selected from groups presentable by R¹ ₃Si,then [O_(1/2)Z⁴] is also presentable by (R¹ ₃SiO_(1/2)) with qincreasing by 1 and w decreasing by 1.

The units [SiR²—CH₂—O—]_(γ) and [SiR²—O]_(j) in formula V may alsoappear for example in multiple repeats, for example as blocks or asindividual or as an alternating units.

The units (SiO_(4/2)), (R¹SiO_(3/2)), (R¹ ₂SiO_(2/2)), (SiR² ₂—X—Y—),(SiR² ₂—CH₂—O) in formula VIII may also appear for example as multiplerepeats, for example as blocks or as individual or as alternating units.

The units (R¹ ₃SiO_(1/2)), [O_(1/2)—(SiR² ₂—X—Y—)_(z)(SiR²₂—CH₂—O)_(i)Z³], [O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR² ₂—CH₂—OZ³], [O_(1/2)Z⁴]in formula VIII may appear for example at multiple points of the polymerbackbone, for example in an ordered distribution or in a randomdistribution.

In a preferred method, at least one of the formula III compounds used isselected from the compounds conforming to the following formula IIIb:

where R¹² may assume the same meanings as defined above and where R¹² informula IIIb preferably, more preferably and even more preferablyassumes the meanings as defined above as respectively preferable, morepreferable and even more preferable for R¹², and where 9 may assumewhole-numbered values not less than 1 and preferably assumes values of 1to 10, more preferably the values 1 or 2 and even more preferably 1.

Particular preference is for the compounds used as including at leastone unit of the general formula III to be the hereinbelow showncompounds numbered 1 to 4, where the compounds 4a to 4u constituterepresentatives of structure 4,

where d may assume whole-numbered values not less than 1, e may assumewhole-numbered values not less than 0, e′ may assume whole-numberedvalues not less than 0 and f may assume whole-numbered values of 0 ornot less than 2, and where R may assume the meanings hydrogen, methyl,ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl,n-pentyl, sec-pentyl(1-methylbutyl or 1-ethylpropyl),isopentyl(2-methylbutyl or 3-methylbutyl), neopentyl, tert-pentyl,n-hexyl, n-octyl, benzyl, phenyl, 2-methylphenyl, 3-methylphenyl,4-methylphenyl, cyclopentyl or cyclohexyl, and where R in the case whenf is unlike 0 denotes hydrogen, and where d in the case when e is 0 ande′ is 0 and f is 0 may assume whole-numbered values not less than 2,

where g may assume whole-numbered values not less than 1 and h mayassume whole-numbered values not less than 0 and the sum of g+h mayassume whole-numbered values not less than 3,

The invention further provides the compounds of formula III having thestructures 3 and 4.

The repeat units [O—CH₂—SiMe₂]_(d) and [—O—SiMe₂]_(e) or respectively[SiMe₂—O—]_(e), and [SiMe₂-CH₂—O—]_(f) in structure 3 each may appear inmultiple repeats for example as blocks or as individual as alternatingunits, for example in a random distribution.

The repeat units [SiMe₂-CH₂—O—]_(g) and [SiMe₂—O—]_(h) in structure 4may appear in multiple repeats for example as blocks or as individual oras alternating units, for example in a random distribution.

A method for producing compounds of the structure 3, which comprisesreacting compounds of structure 1, 2 or 4, with water or alcohols,likewise forms part of the subject matter of the present invention. Thecompounds of structure 3 are obtainable from the compounds of structure1, 2 or 4 by solvolysis with water or alcohols, optionally in thepresence of at least one catalyst. The choice of the R moiety in thechosen solvolysis reagent ROH determines the identity of the R moiety inthe product of structure 3.

A method for producing compounds of the structure 4, which comprisescompound 1 being stored or heated in the presence of an amount ofsubstance of [Me₂SiO] equivalents which is at least equal to the sum ofthe amount of substance of [SiMe₂-O—] groups in the compounds 4 to beproduced. The compounds of structure 4 are obtainable from the compound1 by heating or sufficiently long storage, optionally in the presence ofat least one catalyst, while the ratio of the values of h to g in theproducts of structure 4 which are thus obtainable is directable byaddition of Me₂SiO— equivalents, for example in the form of cyclicdimethylsiloxanes, such as hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane or decamethylcyclopentasiloxane. Thegreater the number of Me₂SiO— equivalents added, the greater the h:gratio. The minimum is a ratio of h:g=0, i.e., in this case the sum totalof the amount of substance of SiMe₂-O— groups in the structure 4compounds to be produced becomes equal to zero and accordingly at leastzero Me₂SiO— equivalents have to be added in the method in this case.The pure compound 1 (>98%, GC) is storable at room temperature withoutadded catalyst for more than 6 months without noticeable change.

d is preferably from 2 to 100, more preferably from 2 to 30 andespecially from 2 to 10.

e is preferably from 0 to 200, more preferably from 0 to 10 and evenmore preferably 0.

e′ is preferably from 0 to 200, more preferably from 0 to 10 and evenmore preferably 0.

f is preferably 0 or from 2 to 100, more preferably 0 or from 2 to 30and even more preferably 0.

R is preferably hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, benzyl,phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, cyclopentyl orcyclohexyl, more preferably hydrogen methyl, ethyl, n-propyl, n-butyl,n-pentyl, n-hexyl or n-octyl and even more preferably hydrogen, methylor ethyl.

g is preferably from 1 to 10, more preferably from 1 to 5 and even morepreferably 1, 2 or 3.

h is preferably from 0 to 10, more preferably 0 to 5 and even morepreferably 0.

The sum g+h is preferably from 3 to 20, more preferably 3 to 10 and evenmore preferably 3 to 5.

The invention further provides a method for producing compounds of thegeneral formula VIII. The compounds of formula VIII are obtainable byreacting mixtures containing compounds of the general formula II and/orof the general formula I preferably with an excess of compounds offormula IV, V, VI, VII or of a second compound of formula VIII, andchoosing the remaining parameters of the method to be the same as in theproduction method for compounds of formula I. Excess means that theamount of substance of total structural units [OCH₂SiR² ₂] present inthe compounds used of formula IV, V, VI, VII or in a second compound offormula VIII assumes a value greater than the amount of substance oftotal structural units [O_(1/2)H] present in the compounds used offormula I and II. In general, when the amount of substance ratios arechosen in this way, the structural units [O_(1/2)H] present in formula Ior II react to form structural units of formula [O₁₂—(SiR²₂—X—Y—)_(a)(SiR² ₂—CH₂—O)_(i)Z³] or of formula [O_(1/2)—(SiR²₂—X—Y—)_(a)(SiR² ₂—CH₂—OZ³], so that w generally assumes the value 0 inthe resulting product of formula VIII; however, under mild conditionsfor example, as for example without added catalyst or for example with aless reactive catalyst or for example at mild temperatures, for examplebelow 120° C., the production of compounds of formula VIII can beperformed such that w assumes a value not less than 1 in the resultingproduct of formula VIII.

When stoichiometric amounts are chosen for compounds of formula III, thestructural units [O_(1/2)H] present in formula I or II may initiallyreact to form structural units of formula [O_(1/2)—(SiR²₂—X—Y—)_(a)(SiR² ₂—CH₂—O)_(i)Z³], so that initial products formed arecompounds of formula VIII where w initially assumes a value greater than0. Stoichiometric means that the amount of substance of total structuralunits [OCH₂SiR² ₂] present in the compounds used of formula IV, V, VI,VII or a second compound of formula VIII assumes a value equal to theamount of substance of total structural units [O_(1/2)H] present in thecompounds used of formula I and II. The structural units of the formula[O_(1/2)(SiR² ₂—CH₂—O)_(i)Z³] may, under suitable conditions, react withstructural units [O_(1/2)H] still present in the reaction mixture; ifthis reaction goes to completion, the products obtained will be of thegeneral formula I when the formula III compound used was selected fromthe compounds of formulae VI where Z¹ is hydrogen or from the compoundsof formula VII where Z² is hydrogen or when the formula III compoundused was selected from the compounds of formulae IV or V, and w assumesin these cases the value 0, u the value 0 and v the value s. In otherwords, compounds of formula VIII can appear as intermediate stages whenusing the method of the present invention for producing compounds offormula I from compounds of formula II.

When a compound of formula VIII was prepared from a compound of formulaII, the sum u+v+w in the produced compound of formula VIII will assumethe value of r in the formula II compound used.

Compounds of formula VIII may be converted into other compounds offormula VIII. For instance, different compounds of formula VIII may beequilibrated with each or one another to exchange the SiR² ₂—CH₂—Ogroups of each or one another, or i or v in formula VIII may beincreased by further reaction with compounds of formula IV, V, VI or VIIor reduced by reaction with compounds of formula I or of formula II.When the reaction of a compound of formula VIII with a compound offormula I or II is carried out using an excess of compounds of formulaVIII, then i or v in the formula VIII compound originally used may belowered, while the compound used of formula I or II may in turn beconverted into a new compound of formula VIII.

Silylated compounds of formula I and silylated derivatives of compoundsof the general formula I are obtainable by contacting the reactionmixture in which the compounds of formulae II and III are reacted witheach other,

or the compounds of formulae II or III,

before, during or after the reaction of compounds of formulae II and IIIwith each other,

or at least one compound of formula I,

with a silylating reagent, for example a chloro-, amino-, alkoxy-,hydroxytrialkyl-, -triaryl- or -triarylalkylsilane,

or by selecting Z— in formula III such that the compound of formula IIIbears a silylating reagent in its structure, for example by selectingthe group Z— in formula III from a trialkyl-, triaryl- ortriarylalkylsilyl group,

or by choosing a combination of these possibilities,

in which case compounds are obtained of the general formula IX,(SiO_(4/2))_(k)(R¹SiO_(3/2))_(m)(R¹ ₂SiO_(2/2))_(p)(R¹₃SiO_(1/2))_(q)[O_(1/2)—(SiR² ₂—X—Y—)_(a)(SiR²₂—CH₂—O)₁Z⁵]_(x)[O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR²₂—CH₂—OZ⁵]_(y)[O_(1/2)Z⁶]_(z)  formula IX,where

-   -   R¹ and R² may assume the same meanings as defined above,    -   a, k, m, p and q may assume the same values as defined above,    -   1 may assume a whole-numbered value not less than 2 and        preferably assumes the meanings 2-100, more preferably 2 to 30        and even more preferably 2-10,    -   x may assume a value not less than 0 and preferably assumes the        meanings 0-20, more preferably 0-10 and even more preferably 0,        1 or 2,    -   y may assume a value not less than 0 and preferably assumes the        meanings 0-20, more preferably 0-10 and even more preferably 0,        1 or 2,    -   z may assume a value not less than 0 and preferably assumes the        meanings 0-10, more preferably 0, 1 or 2 and even more        preferably 0,    -   x+y+z assumes the value r,    -   Z⁵ represents a silyl group attached via a silicon atom, a        siloxanyl group attached via a silicon atom or represents a        hydrogen atom, and    -   Z⁶ may assume the same meanings as Z⁵,        with the proviso that the groups Z⁵ or Z⁶ have to be at least        partly selected from silyl groups.    -   Z⁵ is preferably a silyl group attached via a silicon atom, or        hydrogen and more preferably is hydrogen.    -   Z⁶ is preferably a silyl group attached via a silicon atom or a        siloxanyl group attached via a silicon atom, more preferably a        silyl group attached via a silicon atom and even more preferably        trimethylsilyl, triethylsilyl, triisopropylsilyl,        tert-butyldimethylsilyl, dimethylphenylsilyl or        methyldiphenylsilyl.

l may assume for example the meanings 2, 3, 4, 5, 6, 7, 8, 9, 10 or11-30.

x, y and z may assume for example the meanings 0, 1, 2, 3, 4, 5, 6, 7,8, 9, 10 or 11-20.

Preferably, in this method, the formula II compounds used are compoundsof formula IIa and the formula III compounds used are compounds offormula IIIa, IIIb, IV, V, VI, VII or VIII, more preferably of formulaIIIb and even more preferably of structure 1.

When Z⁶ assumes meanings selected from groups presentable by R¹ ₃Si,then the [O_(1/2)Z⁶] group is also presentable by (R¹ ₃SiO_(1/2)) with qincreasing by 1 and z decreasing by 1. When the simultaneous choice ismade of x as 0 and Z⁵ as hydrogen, then the compound of formula IXcorresponds to a compound of formula I. This is achievable for exampleby the silylating agent including the structure R¹ ₃Si-AG, where the AGgroup represents a hydrolysable leaving group.

Preferably, the compound of formula II is reacted with the silylatingagent before the reaction with compound of formula III. Preferably, thesum total of amount of substance of silylating agent plus amount ofsubstance of [OCH₂SiR² ₂] groups in formula III compound used is chosento be stoichiometric or substoichiometric, based on the amount ofsubstance of SiOH groups in the formula II compound used. AG ispreferably a C₁-C₂₀ alkoxy group, a C₆-C₂₀ aryloxy group, a hydroxylgroup, a halogen atom, a moiety attached via nitrogen, a hydrogen atomor an OSiR¹ ₃ group, more preferably a methoxy group, an ethoxy group, ahydroxyl group, a chlorine atom, a hydrogen atom, an N(H)SiR¹ ₃ group,an N(alkyl)SiR¹ ₃ group, an amino, alkylamino or dialkylamino group, animidazole moiety or an OSiR¹ ₃ group.

Compounds of formula IX where x is above 0 are obtainable for example byusing an excess of compounds of formula III, based on the amount ofsubstance ratio of [OCH₂Si] structure elements in compounds of formulaIII to silanol groups in compounds of formula II.

Compounds of formula IX where x is above 0 may appear as intermediatestages in the course of the reaction of the production method even whenno excess of compounds of formula III, based on the amount of substanceratio of [OCH₂Si] structure elements in compounds of formula III tosilanol groups in compounds of formula II is used.

When compounds of formula I are reacted with a silylating reagent thatincludes the R¹ ₃Si-AG structure, the products obtained likewise conformto formula I with t being lowered by the number of OH groups whichcorresponds to the silylated equivalents and q being raised by thenumber of OH groups which corresponds to the silylated equivalents.

To produce, for example, resins which only have a defined content ofhydroxyl groups (sum total of carbinol groups s+silanol groups t), theratios between the resin and the compound having units of the generalformula III are chosen such that the desired carbinol content isobtained. The remaining unconverted Si—OH groups may remain in theorganofunctional siloxane of the general formula I, or—when a reducedlevel of silanol groups and hence of hydroxyl groups is desired—reactedbefore, during or after the reaction with at least one compound havingunits of the general formula III, with for example silazanes of thefollowing general formula X

where

-   -   R⁹ denotes hydrogen or an optionally —CN— or halogen-substituted        C₁-C₁₀ hydrocarbon residue, and    -   R¹⁰ denotes hydrogen or an optionally —CN— or        halogen-substituted C₁-C₁₀ hydrocarbon residue.

Preferably, the hydrocarbon moieties R⁹ and R¹⁰ have from to 5 carbonatoms. Methyl, ethyl and vinyl are particularly preferred. Hydrogen ispreferred as R¹⁰.

Reacting compounds of the general formulae VI, VII or VIII where Z¹ informula VI, Z² in formula VII and Z³ in formula VIII are eachrespectively other than hydrogen are reacted as compounds of formula IIIwith compounds of formula II gives compounds of formula VIII where Z³ orZ⁴ are at least partly other than hydrogen. Z³ may be for example asilyl group, a siloxanyl group or an alkyl, aryl or acyl groupoptionally substituted with Q¹ and Z⁴ may be a silyl group or asiloxanyl group. Z³ groups that are detachable by solvolysis with proticcompounds can be wholly or partly converted into hydrogen by solvolysisof compounds of formula VIII, and i can be reduced down to 1. Fullsolvolysis of Z³ groups and reduction of i to 1 gives compounds offormula I when Z⁴ is chosen to be hydrogen or w chosen to be 0.Similarly, the Z⁵ groups in compounds of formula IX can be wholly orpartly converted into hydrogen by solvolysis and h can be reduced downto 1. Full solvolysis of Z⁵ groups and reduction of h to 1 givescompound of formula I when Z⁶ was chosen to be hydrogen or z chosen tobe 0.

The invention further provides a method for solvolysis of compounds orintermediate stages obtainable on addition of a silylating agent, forexample solvolysis of compounds of the general formula VIII or offormula IX. This method comprises reacting the silylated intermediatestages/compounds, for example compounds of the general formula VIII orIX, with water, an alcohol such as, for example, methanol, ethanol,propanol or butanol, in which case n-, sec-, iso- or tert-isomers of thealcohols can be used, a silanol such as, for example, triethylsilanol,an OH-functional siloxane (in which case compounds of formula II forexample can be used as OH-functional siloxane) or else when Z³ informula VIII is an acyl group, with a primary or secondary amine suchas, for example, ammonia, butylamine or diethylamine, or with a mixturecontaining one or more of these solvolysis reagents. The solvolysismethod preferably involves the use of water or an alcohol for compoundsof formula VIII or IX. It is preferable for the solvolysis process forcompounds of formula VIII to be carried out with the parameters Z⁴ equalto hydrogen or w equal to 0 and the solvolysis of Z⁴ groups is carriedout to completion and i is reduced to 1 by solvolysis, and so compoundsof the general formula I are obtained.

It is preferable for the solvolysis process for compounds of formula IXto be carried out with the parameters Z⁶ equal to hydrogen or z equal to0 and the solvolysis of Z⁴ groups is carried on to completion and 1 isreduced to 1 by solvolysis, and so compounds of the general formula Iare obtained.

The aforementioned methods may preferably be carried out at temperaturesof 0° C. to 250° C. It is more preferable, however, to use reactiontemperatures of at least 10° C. to 150° C. and especially of 15° C. to120° C. The methods may be carried out without catalysis. The methodscan be improved by adding catalysts. These catalysts are acidic or basiccompounds or metal compounds and have the effect of not only thereaction times but also reaction temperatures can be reduced. Thecatalyst used is preferably an organic or inorganic Lewis acid or Lewisbase, or organic or inorganic Bronstedt acid or Bronstedt base, anorganometallic compound or a halide salt. Preferred acids are carboxylicacids, partially esterified carboxylic acids, especially monocarboxylicacids, preferably formic acid or acetic acid, unesterified or partiallyesterified mono-, oligo- or polyphosphoric acids, unhydrolyzed orpartially hydrolyzed phosphoronitrile chloride, sulfonic acids, alkylhydrogensulfates or acidic ion exchangers. By way of preferred bases itis preferable to use alkylammonium hydroxides, ammonium alkoxides,alkylammonium fluorides or amine bases, guanidine bases or amidinebases. Preferred metal compounds are tin compounds, zinc compounds,aluminum compounds, bismuth compounds or titanium compounds. Preferredorganometallic compounds are organotin compounds, organozinc compounds,organoaluminum compounds, organobismuth compounds or organotitaniumcompounds. Preferred salts are tetraalkylammonium fluorides.

The catalysts used are deactivated after the functionalization reactionof silanol groups, preferably by addition of so-called anti-catalysts orcatalyst poisons, removed by distillation, decanting, centrifuging Orfiltration, adsorbed on a carrier material, precipitated, complexed orextracted, before they are able to lead to any cleavage of Si—O—Sigroups. This side-reaction is dependent on the catalyst used and neednot necessarily occur, so that it may also be possible, as the case maybe, to dispense with deactivating or with removing the catalyst.Examples of catalyst poisons are acids in the case of the use of basesand bases in the case of the use of acids, which in the final analysisleads to a simple neutralizing reaction. The reaction product formedbetween the catalyst and the catalyst poison can either be removed fromthe product, or remain in the product, depending on the use of theproduct. Examples of catalysts removable by distillation are carboxylicacids, for example formic acid, acetic acid, or amine bases, amidinebases or guanidine bases, for example triethylamine, tributylamine,ethyldiisopropylamine, ethylenediamine, tetramethylguanidine,1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene or1,4-diazabicyclo[2.2.2]octane. Examples of catalysts removable bydecanting, filtration or by centrifuging are heterogeneous catalystssuch as, for example, polymer-supported acids or bases, acidic or basicion exchanger, or acidic or basic alumina. Examples of catalysts whichcan be adsorbed, complexed or precipitated are tin compounds, zinccompounds or titanium compounds.

Preference is given to using catalysts which can be removed from theproduct by distillation, more preferably distillatively removablenitrogen bases. The distillatively removable catalysts are characterizedin that they, measured, on the catalyst as pure substance, have a vaporpressure of at least 1 hPa, preferably at least 10 hPa, more preferablyat least 100 hPa and even more preferably at least 1000 hPa attemperatures up to at most 300° C., preferably at most 250° C., morepreferably at most 210° C. and even more preferably at most 180° C.

In the method for producing hydroxyalkylpolysiloxanes of the generalformula I, the amount of compound used as having units of the generalformula III is dependent on the amount r of silanol groups to befunctionalized in the organosiloxane of the general formula II. However,to achieve complete functionalization of OH groups, the compound havingunits of the general formula III must be added in at least equimolaramounts, based on n. When compound having units of the general formulaIII is used in excess, fully reacted compound may subsequently,optionally after thermolytic cleavage, be distilled off or solvolyzed,preferably hydrolyzed, and then optionally likewise be distilled off, orunconverted excess compound of formula III can be removed for exampleusing the methods mentioned. Compounds of formula VIII may appear forexample as intermediate stage in which the excess fully reactedequivalents of compounds of formula III can be detached by thermolysisor solvolysis to obtain compound of formula I.

Furthermore, the formula II organopolysiloxanes used in the method ofthe present invention may contain water which can react, in hydrolysisreactions, with the compounds of formula III or with formula VIIIcompounds which as the case may be can appear as intermediate stagesduring the execution of the method. The consequence is a correspondingextra consumption of compound of formula III. This can be allowed for byusing correspondingly larger amounts of compound of the general formulaIII, preferably by additionally adding two moles of units of formulaIII, based on n, per mole of water. Methods of water determination suchas for example Karl Fischer Titration or Headspace GC are common generalknowledge. Possible hydrolysis products include for example compounds ofstructure 3 or 1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane or(hydroxymethyl)dimethylsilanol. The compounds of structure 3 must beassigned to compounds of formula III and are thus able—once thewater-based extra consumption described is corrected for—to furtherreact the method of the present invention. The1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane does not correspondto a compound of formula III, since n is 1 on both sides of the siloxaneoxygen atom and neither of the two silicon atoms bears a hydrolysablegroup. The hydrolysis products, such as1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane for example, canselectively remain in the product or be removed by, for example,distillative methods or application of vacuum, preferably by heating,after the method of the present invention has been carried out.Alternatively, the water can be removed via suitable methods, forexample by distillation, application of vacuum, heating, reaction withwater-scavenging reagents, adsorption on water-imbibing agents such asfor example molecular sieves or alumina, drying by salts such as forexample magnesium sulfate, sodium sulfate, calcium chloride or potassiumcarbonate, or by combination drying methods, for example by combinationof the recited methods, for example combination of heating andapplication of vacuum, as is possible in a thin-film or short-pathevaporator for example, from the formula II organopolysiloxane to beused before the method of the present invention is carried out. Removingthe water before the method of the present invention is carried out ispreferable. In this case, drying is preferably carried on to a residualwater content of less than 10 000 ppm, more preferably less than 1000ppm and even more preferably less than 200 ppm.

The methods can be carried out not only with solvents or elsealternatively without the use of solvents in suitable reactors. Reducedpressure or superatmospheric pressure or atmospheric pressure (0.1 MPaabsolute) is employed, if appropriate. The methods can be carried out incontinuous operation or in batch operation.

Useful solvents include cyclic or acyclic hydrocarbons, ethers, esters,alcohols, amides, urea derivatives or halogenated organic compounds orsolvent mixtures. When the solvents are used, the preference is forinert, especially aprotic solvents such as aliphatic hydrocarbons, forexample, heptane or decane and aromatic hydrocarbons such as, forexample, toluene or xylene. It is likewise possible to use ethers suchas tetrahydrofuran, diethyl ether or methyl tert-butyl ether. The amountof solvent should be sufficient to ensure sufficient homogenization ofthe reaction mixture. Solvents or solvent mixtures having a boilingpoint/boiling range of up to 120° C. at 0.1 MPa absolute are preferable.

When alcohols are used as solvents, they can convert various compoundsof formula III. For instance, methanol or ethanol can react for examplewith the compounds of structures 1, 2 or 4 to form compounds of thestructure 3. It is similarly possible for alcoholic solvents to cleavethe Z groups in compounds of formula III at the Si—OCH₂ bonds when Z wasselected from groups of the formula XR² ₂Si, converting Z into hydrogenand, if appropriate, reducing n, if appropriate down to where n=1. Theformula III compounds obtained by actions of alcohols can likewise beused in the method of the present invention.

The (hydroxymethyl)polysiloxanes or (hydroxymethyl)-polysiloxane resinsproduced by one of the aforementioned methods can be used for reactionwith isocyanates, for producing urethanes, polyurethanes or polyurethanecopolymers, for reaction with carboxylic acids or with carboxylic acidderivatives, or for producing esters, polyesters or polyestercopolymers.

All the above symbols of the above formulae each have their meaningsindependently of each other unless expressly stated otherwise.

In the examples which follow, unless specifically stated otherwise, allamounts and percentages are by weight, all pressures are 0.10 MPa (abs.)and all temperatures are 20° C. All viscosities were determined at 25°C.

Example 1 Producing a Compound of General Formula I

1000 g of Me-siloxane (α,ω-bishydroxy-terminated polydimethylsiloxanehaving an Mn of 2930 g/mol, determined by ¹H NMR spectroscopy;corresponds to 341.3 mmol of polydimethylsiloxane having 682.6 mmol ofSiOH groups) were reacted at 20° C. with 60.2 g (341.3 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 0.5g of tetramethylguanidine (catalyst) (500 ppm based on Me-siloxane. ¹HNMR and ²⁹Si NMR showed that after 2 hours all SiOH groups had beenconverted into Si—O—SiMe₂-CH₂OH units (hydroxymethyl units). To removethe catalyst, the crude product was purified by thin film distillation(130° C., 10 mbar, 400 g/h). The catalyst passed over in the distillate,leaving behind pure α,ω-bis(hydroxymethyl)polydimethylsiloxane.

Example 2 Producing a Compound of the General Formula I

Example 1 is repeated except that 0.36 g of tetramethylguanidine(catalyst) (360 ppm based on Me-siloxane) is added. The reactionproceeds correspondingly slower and takes 6 hours to reach fullconversion of SiOH groups. Purification is effected as in example 1.

Example 3 Producing a Compound of the General Formula I

Example 1 is repeated except that 0.25 g of tetramethylguanidine(catalyst) (250 ppm based on Me-siloxane) is added. The reactionproceeds correspondingly slower and takes 12 hours to reach fullconversion of SiOH groups. Purification is effected as in example 1.

Example 4 Producing a Compound of General Formula I

1000 g of siloxane (α,ω-bishydroxy-terminated polydimethylsiloxanehaving an Mn of 900 g/mol, determined by ¹H NMR spectroscopy;corresponds to 1.111 mol of siloxane having 2.222 mol of SiOH groups)were reacted at 20° C. with 196 g (1.111 mol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 0.5g of tetramethylguanidine (catalyst) (500 ppm based on siloxane. ¹H NMRand ²⁹Si NMR showed that after 2 hours all SiOH groups had beenconverted into Si—O—SiMe₂-CH₂OH units (hydroxymethyl units). To removethe catalyst, the crude product was purified by thin film distillation(130° C., 10 mbar, 400 g/h). The catalyst passed over in the distillate,leaving behind pure α,ω-bis(hydroxymethyl)polydimethylsiloxane.

Example 5 Producing a Compound of General Formula I

1000 g of Me-siloxane (α,ω-bishydroxy-terminated polydimethylsiloxanehaving an Mn of 2930 g/mol, determined by ¹H NMR spectroscopy;corresponds to 341.3 mmol of polydimethylsiloxane having 682.6 mmol ofSiOH groups) were reacted at 20° C. with 60.2 g of a mixture consistingof 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) toan extent of 95% and of oligomers of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane to an extent of 5%(corresponds in total to 683 mmol of [OCH₂(SiMe₂)] units) and 0.5 g oftetramethylguanidine (catalyst) (500 ppm based on Me-siloxane). Theoligomer of 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexaneconsisted mainly of H—[O—CH₂—SiMe₂]_(n)—OH (n≧1; mainly n<<1;corresponds to a compound of structure 3 for n>1) and ofH—[O—CH₂—SiMe₂]_(n)—O—[SiMe₂-CH₂—O]_(b)—H (corresponds to a compound ofstructure 3 with n=d, b=f, e=0; n≧1, b≧2; mainly n>>1 and b>>2). Thecompounds of structure 3 were formed by moisture acting on2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane. ¹H NMR and ²⁹Si NMRshowed that after 8 hours all SiOH groups had been converted toSi—O—SiMe₂-CH₂OH units (hydroxymethyl units). To remove the catalyst,the crude product was purified by thin film distillation (130° C., 10mbar, 400 g/h). Pure α,ω-bis(hydroxymethyl)polydimethylsiloxane was leftbehind. This example shows that not only2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane but also itsoligomers are suitable for derivitization of SiOH groups.

Example 6 Producing a Compound of General Formula I

Example 1 is repeated except that 0.1 g (100 ppm) of sodium methoxide(catalyst) was used instead of tetramethylguanidine. The reactionmixture was stirred at 20-30° C. for 90 minutes, at which point thecatalyst was neutralized by addition of stoichiometric amounts of aceticacid (formation of sodium acetate). The mixture was stirred at 20-30° C.for a further 60 minutes, the neutralization product methanol wasremoved under reduced pressure and precipitated sodium acetate wasfiltered off to obtain pure α,ω-bis(hydroxymethyl)-polydimethylsiloxane.

Example 7 Producing a Compound of General Formula I

1000 g of silicone oil (α,ω-bishydroxy-terminatedpolymethylvinylsiloxane having a vinyl:methyl ratio of 1:4 and an Mn of2800 g/mol, determined by ¹H NMR spectroscopy; corresponds to 357.1 mmolof polymethylvinylsiloxane with 714.3 mmol of SiOH groups) were reactedat 70-100° C. with 63.0 g (357.2 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 100mg of formic acid (catalyst). ¹H NMR and ²⁹Si NMR showed that after 3hours all SiOH groups had been converted into Si—O—SiMe₂-CH₂OH units(hydroxymethyl units). Then, to deactivate the catalyst, 500 mg oftriethylamine were added to the reaction solution, followed by briefdistillation under reduced pressure (5 mbar) at 80° C., leaving behindpure α,ω-bis(hydroxymethyl)polymethylvinylsiloxane.

Example 8 Producing a Compound of the General Formula VIII

3.40 g of siloxane (α,ω-bishydroxy-terminated polydimethylsiloxanehaving an Mn of 1336 g/mol, determined by ¹H NMR spectroscopy;corresponds to 2.545 mmol of siloxane with 5.09 mmol of SiOH groups)were admixed at 20° C. with 1.00 g (5.67 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 170mg of basic alumina (Brockmann activity I) (catalyst). The mixture wasstirred at 120° C. for 2 hours. ¹H NMR showed that after 2 hours allSiOH groups had been converted to Si—O—[(SiMe₂-CH₂—O)_(i)—H] units(average i equal to around 2).

Example 9 Producing a Compound of the General Formula I

A product produced as per example 8 was admixed with 4.17 g of siloxane(α,ω-bishydroxy-terminated polydimethylsiloxane having an Mn of 1336g/mol, determined by ¹H NMR spectroscopy; corresponds to 3.12 mmol ofsiloxane with 6.24 mmol of SiOH groups). The mixture was stirred at 120°C. for 2 hours. ¹H NMR showed that after 2 hours all SiOH groups hadreacted with Si—O—[(SiMe₂-CH₂—O)_(i)—H] units to form Si—O—SiMe₂-CH₂OHunits (hydroxymethyl units). The alumina was centrifuged off aftercooling down to 20° C., leaving pureα,ω-bis(hydroxymethyl)polydimethylsiloxane in the supernatant.

Example 10 Producing a Compound of the General Formula I

A product produced as per example 8 was admixed with 1.00 g of water(solvolysis reagent, hydrolysis) and 2 mL of 1,4-dioxane. The mixturewas refluxed for 2 hours. ¹H NMR showed that after 2 hours allSi—O—[(SiMe₂-CH₂—O)_(i)—H] units had been converted intoSi—O—SiMe₂-CH₂OH units (hydroxymethyl units) (in accordance with theinvention). The hydrolysis byproduced1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane (not in accordancewith the invention). The alumina was centrifuged off after cooling to20° C. The supernatant was freed of1,3-bis(hydroxymethyl)-1,1,3,3-tetramethyldisiloxane in a kugelrohrevaporator (130° C., 0.1 mbar), leaving behind pureα,ω-bis(hydroxymethyl)polydimethylsiloxane.

Example 11 Producing Compounds of Structure 3

11 g of 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1)were admixed with a few drops of methanol and stored undercover at roomtemperature for 24 hours. NMR analysis showed that about 30% wasunchanged, the remainder (about 70%) being converted into compounds ofthe HO—[O—CH₂—SiR² ₂]_(n)—OMe structure, which corresponds to structuresof formula III with Z═H, Y═OCH₃, R²=Me and n (mean value)=50, orstructures 3 with d (mean value)=50, e=0, f=0 and R=Me.

Example 12 Producing a Compound of the General Formula I

201.2 g of Me-siloxane (α,ω-bishydroxy-terminated polydimethylsiloxane)having an Mn of 3557 g/mol, determined by ¹H NMR spectroscopy;corresponds to 56.6 mmol of polydimethylsiloxane with 113 mmol of SiOHgroups) were reacted at room temperature with 11.06 g (125 mmol ofMe₂Si—CH₂O units) of a mixture of the compounds2,2,5,5-tetramethyl-2,5-disila-1,4-dioxa-cyclohexane (compound 1, about30% fraction) and of an oligomer of formula III Z—[O—CH₂—SiR² ₂]_(n)—Ywith Z═H, Y═OCH₃, R²=Me and n (mean value)=50 (about 70% fraction;corresponds to a compound of structure 3) (product of example 11) in thepresence of 0.39 g (3.39 mmol, corresponds to about 1800 ppm) oftetramethylguanidine (catalyst). ¹H NMR and ²⁹Si NMR showed that after24 hours all SiOH groups had been converted into Si—O—SiMe₂-CH₂OH units(hydroxymethyl units). To remove the catalyst, the crude product washeated to 100° C. at 0.03 Torr for 2 hours. The residue consisted ofα,ω-bis(hydroxymethyl)polydimethylsiloxane.

Example 13 Producing a Compound of the General Formula I

201.2 g of Me-siloxane (α,ω-bishydroxy-terminated polydimethylsiloxane)having an Mn of 3557 g/mol, determined by ¹H NMR spectroscopy;corresponds to 56.6 mmol of polydimethylsiloxane with 113 mmol of SiOHgroups) were reacted at 50° C. with 11.06 g (125 mmol of Me₂Si—CH₂Ounits) of a mixture of the compounds2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1, about30% fraction) and of an oligomer of formula III Z—[O—CH₂—SiR² ₂]_(n)—Ywith Z═H, Y═OCH₃, R²=Me and n (mean value)=50 (about 70% fraction;corresponds to a compound of structure 3) in the presence of 0.106 g(0.92 mmol, corresponds to about 500 ppm) of tetramethylguanidine(catalyst). ¹H NMR and ²⁹Si NMR showed that after 60 minutes 94% of allSiOH groups had been converted into Si—O—SiMe₂-CH₂OH units(hydroxymethyl units).

Example 14 Producing Compounds of Structure 4

1.41 g (8.0 mmol) of 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane(compound 1) and 50 mg of phosphoronitrile chloride (catalyst) werestirred at 20° C. for 18 hours. Thereafter, in addition to compound 1(proportion in mixture: 90%, GC), the compounds of structures 4p, 4q, 4rand 4s were detectable by GC and GC/MS (MS [m/z]: 4p, 264; 4q, 352; 4r,440; 4s, 528; in each case [M⁺]).

Example 15 Producing Compounds of Structure 4

1.76 g (10.0 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 60mg of phosphoronitrile chloride (catalyst) were stirred at 100° C. for 7hours. Thereafter, in addition to compound 1 (proportion in mixture:71%, GC), the compounds of structures 4p and 4q were detectable by GCand GC/MS (MS [m/z]: 4p, 264; 4q, 352; in each case [M⁺]).

Example 16 Producing Compounds of Structure 4

3.50 g (20.0 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and 180mg of Tonsil® (catalyst) were stirred at 100° C. for 4 hours.Thereafter, in addition to compound 1 (proportion in mixture: 63%, GC),the compounds of structures 4p, 4q, 4r and 4s were detectable by GC andGC/MS (MS [m/z]: 4p, 264; 4q, 352; 4r, 440; 4s, 528; in each case [M⁺]).

Example 17 Producing Compounds of Structure 4

3.50 g (19.8 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1), 3.00 g(10.1 mmol) of octamethylcyclotetrasiloxane and 60 mg ofphosphoronitrile chloride (catalyst) were stirred at 20° C. for 2 hours.The solution became viscous. The mixture was left to stand at 20° C. fora further 18 hours without disruption. Thereafter, in addition tocompound 1 (proportion in mixture: 11%, GC), the compounds of structures4a-4u were detectable by GC and GC/MS, predominantly the compounds 4a-e.

Example 18 Producing Compounds of Structure 4

3.50 g (19.8 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1), 7.40 g(20.0 mmol) of decamethylcyclopentasiloxane and 0.12 g ofphosphoronitrile chloride (catalyst) were stirred at 20° C. for 25hours. The solution became viscous. The mixture was left to stand at 20°C. for a further 18 hours without disruption. Thereafter, in addition tocompound 1 (proportion in mixture: 24%, GC), the compounds of structures4a-4u were detectable by GC and GC/MS, predominantly the compounds 4a-e.

Example 19 Producing Compounds of Structure 3

7.06 g (40.0 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) and36.0 mg (2.00 mmol) of water (corresponds to ROH as solvolysis reagentwith R═H) were dissolved in 5 mL of tetrahydrofuran (THF) and stirred at20° C. for 2 days. Thereafter, in addition to compound 1, the compoundsHOCH₂SiMe₂OH, HOCH₂SiMe₂OSiMe₂CH₂OH and compounds of structure 3 withR═H, e=0, d≧1 and f≧2 were detectable by GC and GC/MS. A repeat withaddition of 0.07 g of tributylamine (catalyst) led to an identicalresult.

Example 20 Producing Compounds of Structure 3

0.948 g (5.38 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) wasmixed with 0.172 g (5.38 mmol) of methanol and kept at room temperatureundercover for 7 days. Conversion took place to the compoundHOCH₂Si(OMe)Me₂ and also to compounds of structure 3 (=oligomers withR=Me, e=0, f=0, d=≧2, especially d=2-10); their NMR-spectroscopicallydetermined fraction amounted altogether to about 89%; in addition, 11%of unconverted 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane(compound 1) was detected.

Example 21 Producing Compounds of Structure 3

0.948 g (5.38 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1) wasmixed with 0.344 g (10.6 mmol) of methanol and kept at room temperatureundercover for 24 hours. Conversion took place to the compoundHOCH₂Si(OMe)Me₂ and also to compounds of structure 3 (=oligomers withR=Me, e=0, f=0, d=≧2, especially d=2-10); their NMR-spectroscopicallydetermined fraction amounted altogether to about 91%; in addition, 9% ofunconverted 2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane(compound 1) is detected.

Example 22 Producing Compounds of Structure 3

11.02 g of the product mixture from example 18 were stirred with 0.64 gof methanol (corresponds to ROH as solvolysis reagent with R=Me) at 20°C. for 7 days. Thereafter, GC and GC/MS, in addition to compound 1 (18%,GC), detected compounds of structure 4 (45%, GC) and HOCH₂Si(OMe)Me₂compounds of structure 3 with R=Me, e≧0, d≧1 and f=0, mainlyrepresentatives with e=1 or 2 and d=1 or 2.

Example 23 Producing Compounds of Structure 4

3.50 g (19.8 mmol) of2,2,5,5-tetramethyl-2,5-disila-1,4-dioxacyclohexane (compound 1), 4.45 g(20.0 mmol) of hexamethylcyclotrisiloxane and 0.12 g of phosphoronitrilechloride were stirred at 20° C. for 1 hour. The solution became viscous.Thereafter, GC and GC/MS, in addition to compound 1 (proportion ofmixture: 7% GC), detected the compounds of structures 4a-4s (GC: 4a 38%,4b 11%, 4c 1%, 4d 2.5%, 4e 14%, 4k 1%, 4u 4%; the remainder consisted ofother compounds of structure 4).

The invention claimed is:
 1. A method for producing(hydroxymethyl)polysiloxanes of the general formula I(SiO_(4/2))_(k)(R¹SiO_(3/2))_(m)(R¹ ₂SiO_(2/2))_(p)(R¹₃SiO_(1/2))_(q)[O_(1/2)—(SiR² ₂—X—Y—)_(a)SiR²₂—CH₂—OH]_(s)[O_(1/2)H]_(t)  formula I, which comprises reactingsilanol-containing organosiloxanes of the general formula II(SiO_(4/2))_(k)(R¹SiO_(3/2))_(m)(R¹ ₂SiO_(2/2))_(p)(R¹₃SiO_(1/2))_(q)[O_(1/2)H]_(r)  formula II with cyclic or acycliccompounds which include at least one unit of the general formula IIIZ—[O—CH₂—SiR² ₂]_(n)—Y  formula III where R¹ denotes a hydrogen atom ora cyclic or acyclic, linear or branched, aromatic or aliphatic orolefinic, saturated or unsaturated C₁-C₂₀ hydrocarbon, C₁-C₂₀hydrocarbonoxy or C₄-C₄₀ polyether moiety optionally substituted with Q¹and optionally interrupted by one or more heteroatom-containing groupsQ², R² denotes a cyclic or acyclic, linear or branched aromatic oraliphatic or olefinic, saturated or unsaturated C₁-C₂₀ hydrocarbon,C₁-C₂₀ hydrocarbonoxy, C₄-C₄₀ polyether or Si₁-Si₂₀ siloxanyl moietyoptionally substituted with Q¹, optionally interrupted by one or moreheteroatom-containing groups Q² or containing one or moreheteroatom-containing groups Q², Q¹ denotes a heteroatom-containingmonovalent moiety, Q² denotes a heteroatom-containing divalent moiety ora heteroatom-containing trivalent moiety, Z represents hydrogen, a groupX—SiR² ₂—, or combines with Y to represent a bonding electron pair, Xrepresents a group R², a siloxane group or a bonding electron pair to Yor may be bonded to Y or X combines with Y to denote an oxygen atom ordenotes an oxygen atom attached to Y, Y represents the meanings of R² orQ¹ or Q² or represents a siloxane moiety or a hydrolysable groupinclusive hydroxyl or combines with Z to represent a bonding electronpair and may be attached to Z via X and may be interrupted by one ormore optionally substituted siloxane groups or combines with X to denotean oxygen atom, with the proviso that Y in the case of n=1 denotes ahydrolysable group or a siloxane moiety which contains at least onehydrolysable group or combines with X to denote an oxygen atom or isattached to X or combines with Z to represent a bond, s representsvalues of at least 1, r represents values of at least 1, t representsvalues of at least 0, n represents values of at least 1, the sum s+trepresents the value of r, k, m, p, q denote values not less than zero,with the proviso that the sum k+m+p+q denotes a sum of at least 2, arepresents the value 0 or
 1. 2. The method for producing(hydroxymethyl)polysiloxanes as claimed in claim 1, wherein thesilanol-containing organosiloxanes/organosiloxane resins used of formulaII are compounds conforming to the following formula IIa:H[OSiR¹¹ ₂]_(α)OH  formula IIa, where α denotes whole-numbered values of2 to 20 000 and R¹¹ denotes methyl, ethyl, vinyl, allyl or phenyl. 3.The method for producing (hydroxymethyl)polysiloxanes as claimed inclaim 1, wherein the formula III compounds used are compounds conformingto the following formula IIIa:Z—[O—CH₂—SiR¹² ₂]_(n)—Y  formula IIIa, where R¹² is methyl, ethyl,vinyl, allyl, phenyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, tert-pentoxy or n-hexoxy,and n, Y and Z represent the same meanings as defined above.
 4. Themethod for producing (hydroxymethyl)polysiloxanes as claimed in claim 1,wherein the formula I product produced are the following compounds offormula Ia:HOCH₂SiR¹² ₂[OSiR¹¹ ₂]_(α)OSiR¹² ₂CH₂OH  formula Ia, where α denoteswhole-numbered values of 2 to 20 000 and R¹¹ and R¹² have theabove-defined meanings, by reacting compounds of formula IIa withcompounds of formula IIIa.
 5. The method for producing(hydroxymethyl)polysiloxanes as claimed in claim 1, wherein at least oneof the formula III compounds used is selected from compounds of thefollowing general formulae IV, V, VI, VII or VIII:

where R¹ in the formula VIII represents the same meanings as definedabove, R² in the formulae IV-VIII represents the same meanings asdefined above, β, γ, δ, ε represent the same meanings as n as definedabove, i is a whole-numbered value not less than 2, j in formula Vdenotes a whole-numbered value not less than 0, k, m, p and q and theirabove-defined sum in formula VIII represent the same values as definedabove, u in formula VIII represents a value not less than 1, v informula VIII represents a value not less than 0, w in formula VIIIrepresents a value not less than 0, Y¹ in formula VI represents a moietyR², a moiety —O—(SiR² ₂—CH₂—O)_(b)Z¹, a hydrogen atom or a hydrolysablegroup, with the proviso that Y¹ when δ in formula VI represents themeaning 1 represents a hydrolysable group inclusive alkoxy, aryloxy, orhydroxyl, or a hydrogen atom, or represents a moiety —O—(SiR²₂—CH₂—O)_(b)H with b not less than 2, b represents values not less than1, Y² in formula VII represents a moiety R², a moiety —O—(SiR²₂—CH₂—O)_(c)Z², a hydrogen atom or a hydrolysable group inclusivehydroxyl, c represents values not less than 1, Z¹ represents a hydrogenatom, a silyl group attached via a silicon atom or a siloxanyl groupattached via a silicon atom, Z² represents a hydrogen atom, a silylgroup attached via a silicon atom, a siloxanyl group attached via asilicon atom, or—when ε in formula VII represents a value not less than2 or Y² is a hydrolysable group—represents an alkyl, aryl or acyl groupoptionally substituted with Q¹ or interrupted by one or more groups Q²,Z³ represents a hydrogen atom, a silyl group attached via a siliconatom, a siloxanyl group attached via a silicon atom, or—when i informula VIII represents a value not less than 3—represents an alkyl,aryl or acyl group optionally substituted with Q¹ or interrupted by oneor more groups Q², Z⁴ represents the same meanings as Z¹, a representsthe same meanings as defined above.
 6. The method as claimed in claim 1,wherein at least one of the formula III compounds used is selected fromthe compounds conforming to the following formula IIIb:

where R¹² represents the same meanings as defined above and where φrepresents whole-numbered values not less than
 1. 7. The method asclaimed in claim 1, wherein at least one silylating agent is added andthe resultant silylated intermediate is converted into compounds offormula I by solvolysis with protic compounds.
 8. The method as claimedin claim 1, wherein at least one of the compounds involved is reactedwith a silylating agent having the structure R¹ ₃Si-AG, where the AGgroup represents a hydrolysable leaving group.
 9. The method as claimedin claim 1, wherein an excess of compounds of formula III is used andwherein resultant intermediate compounds of formula VIII are wholly orpartly converted into compounds of formula I by solvolysis with proticcompounds or by thermolysis, wherein excess means that the amount ofsubstance of total structural units [OCH₂SiR² ₂] present in the formulaIII compounds used represents a value greater than the amount ofsubstance of total structural units [O_(1/2)H] present in the formula Icompounds used.